Optical viewing apparatus such as binoculars and telescopes are widely used to magnify and view objects from afar. A common problem encountered with these apparatus is that the viewed image is often blurry and unclear due to movement of the viewing device caused, either intentionally or accidentally, by the individual operating the device. To alleviate this problem, image stabilizers employing image processing techniques are now commonly used in such apparatus, as well as in other viewing apparatus, to produce a sharp, clear, stable image. Image stabilizers are well known in the art. See K. Uormori et al., Automatic Image Stabilizing System by Full-Digital Signal Processing, IEEE Trans. on Consumer Electronics, Vol. 36, No. 3, at pp. 510-519, August 1990; M. Oshima et al., VHS Camcorder with Electronic Image Stabilizer, IEEE Trans. on Consumer Electronics, Vol. 35, No. 4, at pp. 749-758, November 1989; Y. Egusa et al., An Electronic Video Camera Image Stabilizer Operated On Fuzzy Theory, IEEE Conf. on Fuzzy Systems, at pp. 851-858, March 1992.
Conventional image stabilizers used in hand-held viewing apparatus require the use of large image matching fields in order to produce motion-compensated stabilized images. The disadvantage of such systems is that processing a large image matching field requires mathematically complex, time-consuming image processing techniques. An additional disadvantage of such systems is their expense. It is, therefore, an object of this invention to provide an image stabilization system which processes a small selectable portion of the viewed image in order to produce a clear motion-compensated stabilized image without the foregoing limitations found in conventional image stabilizers.